<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>

  <body>
    <div id="app"></div>
    <template id="pengfan">
      <h2>{{info.name}}</h2>
      <button @click="changeInfo">改变info</button>
      <button @click="changeInfoName">改变info.name</button>
      <button @click="changeInfoNbaName">改变info.nba.name</button>
    </template>
    <script src="../js/vue.js"></script>
    <script>
      Vue.createApp({
        template: "#pengfan",
        data() {
          return {
            info: { name: "pengfan", age: "18", nba: { name: "kobe" } },
          };
        },
        watch: {
          //默认情况下我们的侦听器只会针对监听的数据本身的改变(内部发生的改变是不能侦听)
          // info(newInfo, oldInfo) {
          //   console.log("newInfo: ", newInfo, "oldInfo", oldInfo);
          // },

          //深度侦听/立即执行（一定会执行一次）
          info: {
            handler: function (newInfo, oldInfo) {
              console.log(
                "newValue:",
                newInfo.nba.name,
                "oldValue:",
                oldInfo.nba.name
              );
            },
            deep: true, // 深度侦听
            // immediate: true //立即执行
          },
        },
        methods: {
          changeInfo() {
            this.info = { name: "kobe" };
          },
          changeInfoName() {
            this.info.name = "kobe";
          },
          changeInfoNbaName() {
              this.info.nba.name = "james"
          },
        },
      }).mount("#app");
    </script>
  </body>
</html>
